I've read suggestions that contextual menu items be arranged in a circle around the mouse cursor when the menu is activated, since Fitz's Law suggests that each target would be easier to hit.

However, I've never seen this in practice. (I can think of a few simple reasons: text is hard to fit in the space afforded by a wedge-shaped target, it's not a standard pattern and is perceived to be too confusing, etc.)

Are the potential benefits just not worth the trade-off? Are there examples that work that I'm unaware of?

10 Answers
10

I have seen radial menus few times. I have tested a Firefox addon that arranged contextual menu in a circle. Also it was used in some computer games (Temple of Elemental Evil comes to mind when I think about it). It somehow didn't work.

It is much easier to scan a list of options (your eyes move top-down) than options arranged in a circle (your eyes must move in many directions).

Not all options are equal. Some are more important or more frequently used (should be closer to mouse pointer according to Fitz's Law) than others.

You really have a problem with longer items and subitems. The game I mentioned earlier managed to handle it quite nicely visualy, by rotating all the options around the central point. The problem is that when there are more options, you have to read some of them from down to up, others from left to right and the rest goes from top to down.

I think radial contextual menus can work in specific situations (low number of options, items can be represented as icons without a text, etc.). But generally they're not really a good idea.

"You really have a problem with longer items and subitems." -- How so? Many radial menus are multi-level (the sims, Maya marking menus, etc). Multi-line item labels seem more natural to deal with in a radial menu than a linear one.
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Robert FraserAug 10 '10 at 8:51

I had similar experiences - also with ToEE and IIRC the Pools of Radiance remake. However, I found most implementations seriously lacking in "grease" - i.e. assuming that "circular menu" makes it so much better that response times, visual cues, going back and forth etc. don't matter anymore.
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peterchenDec 16 '10 at 14:38

Two comments on the accepted answer: (1) The correct term is Fitts' Law rather than Fitz's Law, (2) neither of the first two bulleted points is supported by research on this topic.
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user1757436Jan 15 '13 at 17:00

What does this mean? Should we program
pie menus into our bitmapped window
systems tomorrow and expect a 15-20%
increase in productivity since users
can select items slightly faster with
pie menus. Pie menus seem promising,
but more experiments are needed before
issuing a strong recommendation.
First, this experiment only addresses
fixed length menus, in particular,
menus consisting of 8 items - no more,
no less. Secondly, there remains the
problem of increased screen real
estate usage, In one trial a subject
complained because the pie menu
obscured his view of the target prompt
message. Finally, the questionnaire
showed that the subjects were almost
evenly divided between pie and linear
menus in subjective satisfaction. Many
found it difficult to "home in on" a
particular item because of the unusual
activation region characteristics of
the pie menu.

Advantages:

Better for repeated use as they can be learned in muscle memory

Faster to select a particular item

Lower error rate (especially when implemented correctly, such that the hit target for an area is the entire region)

More natural for sub-menus

Disadvantages:

Implementation

Harder to scan

Large; can cover up content

Max 12 items

Bad for variable-length lists or items that may move in position

Unfamiliar

Seem not to appeal to "techy" users

Successful uses of radial menus:

Many video games, notably The Sims series. This game is worth playing if you're thinking about them, just to see how much they improve the experience

Maya, blender, and other 3D packages

Mouse gestures in Opera and other browsers (invisible radial menu - but basically the same thing)

While not radial, the windows start menu's nonlinear design. On Win7, from clicking start, I can very easily access my pinned icons, "All programs", the different "places" on the right, shut down, or the search box

Ditto office 2007, in particular the set of formatting tools that appear above a selection. In fact if you right-click on a selection in Office 2010, you get:

A nonlinear menu! Not radial by any means, however many of the important options are distinguished by angle from the cursor as well as distance.

I think one problem pie menus have suffered is that I’ve also seen a lot of bad implementations of pie menus. e.g. If items don’t appear in a predictable place, you lose the muscle-memory advantage. If the selection slices don’t extend far enough, you lose the larger target advantage.
–
Robert FisherAug 11 '10 at 19:56

@Robert Fisher: Full Ack. I'd love to play with a good implementaiton.
–
peterchenDec 16 '10 at 14:43

Basically they explain that radial menus can be a great way to display a right click type of contextual menu in touch devices. Once a user gets used to the initial format, frequent users find that speed of use increase in frequent users.

A good example of this would be in games. A lot of games favor a radial menu over a list menu for speed-of-use. In a fast-paced environment such as a game, radial menus go a long way to helping a user make a selection for their given scenario.

My iOSContextualMenu open source code is a good example of radial menus used in touch devices. Here's a couple of screenshots to show how it could be implemented!

Radical contextual menus can be harder to program for than vertical list menus. There are less existing libraries or components for it, and the programmer might need to write custom code to position each menu item.

Not quite the same, but the wacom pointing device I am using has a circle menu. Clicking the center of the physical circle brings up a on screen display, touching along the outer circle skips through the options and selects a tool accordingly.

I think radial menus have more of a place in touch applications rather than WIMP applications. For example, Cabinet -- a pdf reader for iOS -- uses radial menus for highlighting. It works remarkably well on a touch device since it is very natural to touch and then slide your finger. Not only does it work well, but it's a delight to use.

The main advantage I see on touch devices is that you tend to build muscle memory for the options you use most, which becomes a very natural way to learn what would otherwise be a somewhat convoluted gesture. You get the benefits of gesture input without the steep learning curve often associated with gestures.

As for the question in the title bar: Are they better? Like with nearly all ux questions, the answer is "it depends". They are better for some tasks, but not better for all.